Severe thunderstorms have swept the big cities and the heat is done! It was another hot early afternoon before the storm bearing front arrived following a sultry overnight which saw lows no cooler than 79 in Boston, 80 at LaGuardia Airport, NY, 79 in Philadelphia and 82 in DC. If the temp doesn’t fall below this number before midnight, this would be a record warmest night for June.

As i’ve been stating for days now the heat leaves the Northeast today and next up comes a significant cooldown. A deepening trough which will become the tracks in which air originating from north of Hudson Bay will come all the way down through the Great Lakes and into the Mid-Atantic. NYC could well stay in the 60s Tuesday, Wednesday while DC holds in the low 70s. New England may see mid-60s just with nights falling into the 40s.

While we see the trough in the east, it’s the monster ridge building from the S Plains up into the Central Rockies which will help deepen and force the crisp air from the arctic southeastwards.

Yes, we’re about to see some mighty impressive numbers throughout the Great Basin, Rockies and Plains over the next 7 days.

While Houston to El Paso to Dallas becomes the centre point of 100s this weekend, watch as Denver tops 100 and hold in the 100s through at least Wednesday as the core intensifies. Salt Lake should see one or two 100-degree days also but according to the model, the ridge will push into the Plains with a core over South Dakota by Wednesday. Could see 110 all the way to North Dakota or certainly South Dakota by midweek as it’s the NW trough and storm will cuts east, kicking the heat east too.

Eastern Montana could see highs of 104-106, maybe warming in such cities as Miles City and Glasgow. Even this far north we could see just as many 100s as Denver.

Here is the latest run off the ECMWF for the next week.